Greeley may host first large-scale digester

By Anna Austin

Posted January 6, 2010, at 12:18 a.m. CST

A city in west central Colorado is working to further pursue plans to construct a waste-to-energy facility that would utilize local agricultural and food processing waste streams to produce biogas for electricity generation, a project which could result in the state's first large-scale anaerobic digestion operation.

In late January 2009, Greeley, Colo., was awarded $82,500 to conduct a feasibility analysis to look at the development of a Greeley Clean Energy Park, funding which was part of several New Energy Economic Development grants provided by Colorado Gov. Bill Ritter's Energy Office through the state Clean Energy Funds.

According to the recently completed study, which was conducted by Symbios Technologies LLC, the most manageable and profitable scenario for a first-phase GCEP project would be a 2-megawatt anaerobic digester with a combined-heat-and-power unit for electricity generation, capable of processing more than 500 tons per day of waste from three main waste sources-cow manure from a JBS feedlot, and waste from Leprino Foods Cheese Plant and the city water pollution control facility-into more than 800,000 cubic feet of biogas per day which would be converted into approximately 16 million kilowatt-hours of electricity per year.

The facility could be built for an estimated all-in capital cost of approximately $17.3 million and would yield a 3.7 percent internal rate of return if funded with no public financing.

The study found that the GCEP is uniquely positioned to host the state's first large-scale anaerobic digester project because of key attributes not found at any other known site in Colorado combine to create an economic and environmental advantage over other potential uses of the project partners' wastes. Attributes include but aren't limited to a cost share opportunity with the water pollution control facility, which is located adjacent to the GCEP site and includes an existing digester and de-watering plant that is budgeted for approximately $5 million in improvements that could be reallocated for a community digester project in addition to other infrastructure synergies; short waste hauling distancing from the projects three major possible waste providers; close proximity to energy demands and a unique confluence of significant high-energy waste generators, allowing for economies of scale not possible at other sites.

Bruce Biggi, Greeley's economic development manager, said now the city is seeking funding for a phase two development planning effort. "The development planning effort should answer a few of the report's unanswered questions, and more importantly, address the key elements needed to move forward constructing an anaerobic digestion project," Biggi said. "For example: site selection, permitting, partnership formation, project funding and design."

Biggi added that ideally, project construction would begin prior to the end of this year to benefit from currently available stimulus funding. "This is a very ambitious schedule," he said. "We will have to make sure that the process progresses seamlessly from start to finish."